Infrared glasses convert invisible light into visible colors

A team from the Beijing Institute of Technology has developed eyeglasses that allow wearers to see infrared light, which is normally invisible to humans. The device captures infrared photons using mercury telluride colloidal quantum dots and converts them into electrical charges that drive an OLED layer embedded in a transparent lens. The system renders longer-wavelength infrared as red and shorter-wavelength infrared as a red-cyan mixture, overlaying this information on the wearer's normal field of view.

Human eyes cannot detect infrared because individual infrared photons lack the energy to trigger retinal photoreceptors. Many animals, including rattlesnakes, vampire bats, and certain beetles, perceive infrared naturally, while bees and birds see ultraviolet light. Humans are limited to wavelengths between roughly 400 and 700 nanometers, covering less than one hundredth of a percent of the electromagnetic spectrum.

Previous infrared-to-visible conversion systems typically represented all infrared as a single color. The new glasses distinguish different infrared wavelengths and display them as varying hues, a capability the researchers describe as a paradigm shift in visual prosthetics and augmented reality. The findings were published last week in the journal Science Advances.

The prototype weighs about 23 grams and uses a beige plastic frame with the display covering only one eye. In laboratory tests, researchers shone infrared light onto shapes and moving objects; the glasses rendered the infrared in shades of red or red-cyan overlaid on visible light. The team notes that practical applications for everyday users remain unclear at this stage.

A separate group at the University of Science and Technology of China recently demonstrated a prototype contact lens with similar infrared-to-color conversion. Both devices are still in the laboratory and testing phase. Researchers from both teams view their work as steps toward future "super vision" aids that could expand human perception beyond its evolutionary limits.

The glasses' OLED layer contains two color channels: a red layer that activates first and a cyan layer that triggers only when the red layer is saturated by stronger or shorter-wavelength signals. This intensity-dependent color mapping allows the wearer to discriminate infrared wavelength differences in real time.

The researchers suggest the technology could eventually support molecularly sensitive substance identification, navigation in degraded visual environments, and high-fidelity augmented reality. No timeline for commercial availability or further development stages was provided in the publication.